Submission karma is utterly worthless. All it means is you submit tons of shit, by hand or by bot. In the last year or two there's been a handful of accounts that made the Leaders list [0] by auto or mass submitting generic tech sites (techcrunch, ars, wired etc... really "safe" stuff), even a couple of company spammers were on it at one point! There's no way to win that contest, but more importantly it's not a measure of anything valuable.
Comment karma is worth paying attention to because it doesn't hinge on being the first to submit whatever AOL just shat out.